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ClownMDEmu

github.com

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Spec score 8.9 #3 of 29 in Sega Genesis Emulators

What it is

ClownMDEmu is a free emulator for the Sega Mega Drive, also known as the Sega Genesis. Its self-contained core is provided as a library, with a browser version available to try online. The maker also offers a standalone frontend with debugging menus and a libretro frontend for compatible hosts such as RetroArch and clownlibretro. The core can be built with CMake, but Git submodules must be initialized before compiling. Its design targets C89, integer-only logic, and avoids dynamic memory and global state. Emulator state is stored in a relocatable structure without pointers, supporting save states and the possibility of multiple instances. Audio is output separately for FM and PSG at native sample rates; video is provided one scanline at a time in indexed format. The maker describes a balance between correctness and performance, and notes that some standard Mega Drive features remain unemulated, including areas of 68k exceptions and VDP rendering. ClownMDEmu is free software under AGPLv3 or any later version.

Spec sheet

What it does
ClownMDEmu emulates Sega Mega Drive, also called Sega Genesis, hardware.Read 15 Oct 2026 · github.com
Purpose
ClownMDEmu is an emulator for the Sega Mega Drive, also known as the Sega Genesis.Read 2 Oct 2026 · github.com
License
ClownMDEmu is free software licensed under the AGPLv3 or any later version.Read 2 Oct 2026 · github.com
AppImage install
The Linux AppImage is a single executable file that needs its executable bit enabled and does not require package installation.Read 15 Oct 2026 · appimage.github.io
Apple platform inclusion
The Apple RetroArch listing includes ClownMDEmu as a Sega MD/CD core and supports Mac, iPhone, iPad and Apple TV.Read 15 Oct 2026 · apps.apple.com
Audio and video output
The core outputs FM and PSG audio separately at native sample rates and video one scanline at a time in indexed format.Read 2 Oct 2026 · github.com
Browser version
The standalone frontend README links to a browser version at clownmdemu.clownacy.com.Read 15 Oct 2026 · github.com
Build
The core can be built using CMake, and its repository notes that Git submodules must be initialized before compiling.Read 2 Oct 2026 · github.com
Build system
CMake is supported, and compilation requires initializing the repository's Git submodules.Read 15 Oct 2026 · github.com
Community history
The Mega Drive Developers Collective thread records the project beginning as an incomplete emulator in September 2021 and being released early because feature completeness was considered open-ended.Read 15 Oct 2026 · board.mddc.dev
Core design
The repository contains a self-contained emulation core designed for portability and implemented as a library.Read 2 Oct 2026 · github.com
Core language
The emulation core targets C89 so it can compile with a wide range of compilers.Read 15 Oct 2026 · github.com
Debugger
The standalone frontend includes debugging menus intended for emulator and homebrew work.Read 15 Oct 2026 · github.com
Frontend language
The reference standalone frontend is written in C++20 and uses SDL3 and Dear ImGui.Read 15 Oct 2026 · github.com
Incomplete emulation
The maker notes that some standard Mega Drive features remain unemulated; the TODO lists incomplete 68k exceptions and unimplemented reset instruction and VDP rendering features.Read 2 Oct 2026 · github.com
Independent description
EmuNations describes the emulator as active, portable across Windows, Linux and browser use, and equipped with debugging tools.Read 15 Oct 2026 · emunations.com
Independent feature report
EmuNations reports Motorola 68000 instruction durations, save data, debugger support and accurate window-plane emulation.Read 15 Oct 2026 · emunations.com
Integer-only design
The core avoids floating-point arithmetic for emulation logic, with limited build-time exceptions for generated constants.Read 15 Oct 2026 · github.com
Libretro capabilities
The core supports saves, save states, rewind, netplay, cheats, remapping, softpatching and subsystem loading in RetroArch.Read 15 Oct 2026 · docs.libretro.com
Libretro integration
An official frontend exposes ClownMDEmu as a libretro core for use with libretro implementations such as RetroArch and clownlibretro.Read 2 Oct 2026 · github.com
Licence
ClownMDEmu is free software under the GNU AGPLv3 or any later version.Read 15 Oct 2026 · github.com
Limit: adoption
The maintainer said manual core download and installation was a major barrier to RetroArch adoption before buildbot integration.Read 15 Oct 2026 · forums.libretro.com
Limit: build friction
A Libretro user reported trouble compiling on Linux with the direct Makefile workflow, while another recommended CMake.Read 15 Oct 2026 · forums.libretro.com
Limit: incomplete emulation
The project TODO lists incomplete 68K exceptions, VDP timing and FIFO behavior, Z80 instructions and interrupt timing, EEPROM, cartridge mappers, Master System, Game Gear, 32X and parts of Mega CD.Read 15 Oct 2026 · github.com
Limit: maturity
The same Reddit discussion said ClownMDEmu was not ready to replace established Genesis emulators at that time.Read 15 Oct 2026 · reddit.com
Limit: Mega CD timing
A user reported sped-up Sonic CD FMV without audio, and the maintainer attributed it to incomplete Mega CD timing during CD reads.Read 15 Oct 2026 · clownacy.wordpress.com
Limit: save compatibility
The maintainer says EEPROM is not emulated and SRAM files may not be compatible with every other emulator because cartridge save layouts differ.Read 15 Oct 2026 · clownacy.wordpress.com
Linux requirement
The AppImage catalog warns that the build uses the system C library and may require glibc 2.34 or newer.Read 15 Oct 2026 · appimage.github.io
Maintainer
The GitHub maintainer profile describes Clownacy as a programming professional and Mega Drive hobbyist and lists England as the location.Read 2 Oct 2026 · github.com
Maker profile
The GitHub maintainer profile identifies Clownacy as a programming professional and Mega Drive hobbyist based in England.Read 15 Oct 2026 · github.com
Memory design
The core avoids dynamic allocation and keeps emulator state in relocatable structures without global state.Read 15 Oct 2026 · github.com
Notable update
Version 1.6.8 added DMA-related 68K delays, ZIP ROM loading, improved cheat controls and fixes for file-loading races and Steam Deck input.Read 15 Oct 2026 · github.com
Notable update date
EmuNations lists version 1.6.12 dated 18 September 2026.Read 15 Oct 2026 · emunations.com
Official frontends
The project lists a standalone debugging frontend and a libretro frontend for RetroArch-compatible environments.Read 15 Oct 2026 · github.com
Performance and accuracy
The maker says the emulator balances correctness with performance and may be more high-level than accuracy-focused alternatives.Read 2 Oct 2026 · github.com
Portability
The core targets C89, integer-only logic, no dynamic memory, no global state, and code that avoids undefined or implementation-defined behavior.Read 2 Oct 2026 · github.com
Portable core
The repository provides a self-contained emulation core designed for portability.Read 15 Oct 2026 · github.com
Praise: accuracy
A Libretro forum post praises cycle-level timing and faithful 68K, Z80, VDP and audio emulation for developers and preservationists.Read 15 Oct 2026 · forums.libretro.com
Praise: debugger
A Reddit commenter singled out the debugger as especially interesting while describing the project as a passion project.Read 15 Oct 2026 · reddit.com
Praise: lightweight design
The same forum post characterizes the core as written in C with no external dependencies and suitable for hardware-behavior testing.Read 15 Oct 2026 · forums.libretro.com
Praise: multitap support
Version 1.6.7 added Sega Team Player support for up to eight controllers and Electronic Arts 4 Way Play support for up to four.Read 15 Oct 2026 · github.com
Public interface
The library exposes a low-level interface with separate native-rate FM and PSG audio and scanline-based indexed video output.Read 15 Oct 2026 · github.com
Rating on Apple App Store
3.9 out of 5 from 8 ratingsRead 15 Oct 2026 · apps.apple.com
Save files
RetroArch stores Mega Drive saves as SRM files and Mega CD saves as BRM files, while states use state-numbered files.Read 15 Oct 2026 · docs.libretro.com
Save-state design
The core keeps state in a relocatable struct without pointers, which the maker says supports simple fast save states and the possibility of multiple emulator instances.Read 2 Oct 2026 · github.com
Security guidance
AppImage documentation warns that applications are generally not independently verified and suggests optional Firejail sandboxing.Read 15 Oct 2026 · appimage.github.io
Standalone frontend
An official standalone frontend includes debugging menus and is written in C++20 using SDL3 and Dear ImGui.Read 2 Oct 2026 · github.com
Supported ROM formats
The libretro core accepts BIN, MD, GEN, CUE, ISO and CHD content extensions.Read 15 Oct 2026 · docs.libretro.com
Third-party app inclusion
The Google Play OpenConsole TV listing says its open-source libretro cores include ClownMDEmu for Sega Genesis support.Read 15 Oct 2026 · play.google.com
Unsupported frontend features
Libretro documentation marks rumble, sensors, camera, location, disk control and several metadata features as unsupported.Read 15 Oct 2026 · docs.libretro.com
Video timing
The core reports 59.94 FPS for NTSC and 50 FPS for PAL, with a 320 by 224 base geometry and 512 by 480 maximum geometry.Read 15 Oct 2026 · docs.libretro.com

Plans and prices

ClownMDEmu Free free software AGPLv3 or later · frontend required to run games Read 15 Oct 2026 · github.com

Every ClownMDEmu plan and price →

Strong points and limits

Strong points

  • Browser version can be tried online.
  • Official frontend includes debugging menus.
  • Core supports save states.
  • Free software under AGPLv3 or later.

Limits

  • Some standard Mega Drive features remain unemulated.
  • Git submodules must be initialized before compiling.
  • The maker says it may be more high-level than accuracy-focused alternatives.

Who it suits

ClownMDEmu may suit Mega Drive emulation users who want a browser version, a standalone desktop frontend or a libretro core. Developers can build its library with CMake after initializing the repository's submodules.

ClownMDEmu in depth

Read the full write-up

Overview

ClownMDEmu emulates the Sega Mega Drive, also known as the Genesis, through a browser build, a standalone frontend or libretro-compatible software. It suits players comfortable choosing among those routes, as well as developers interested in a portable emulation library. Its flexible frontends are a strength; unfinished hardware emulation is the key reason to look elsewhere.

Key features

ClownMDEmu separates its emulation core from the interfaces that run it. That is useful for integrating the library into different environments, but players seeking one conventional desktop application may find the split less direct.

Browser, standalone and libretro options: The browser version offers a way to try the emulator online. The official standalone frontend includes debugging menus, while the official libretro frontend makes the core usable in compatible hosts such as RetroArch and clownlibretro. The choice is valuable for users with a preferred setup, though the standalone build and libretro route are distinct frontends rather than one unified interface.

Portable core: The library targets C89, uses integer-only logic, avoids dynamic memory and global state, and is designed to avoid undefined or implementation-defined behavior. Those constraints favor portability and predictable integration. Building it requires CMake, and Git submodules must be initialized before compiling, so source builds are better suited to developers than casual players.

Save states and instances: The core keeps its state in a relocatable struct without pointers. The maker says that design supports simple, fast save states and the possibility of multiple emulator instances. Save states are supported, a practical advantage for players who want to preserve progress.

Separated output: FM and PSG audio are output separately at native sample rates, while video is delivered one scanline at a time in indexed format. That fine-grained output is useful to frontend developers; most players will care more about whether the games and features they need are emulated.

Emulation trade-offs: The maker describes a balance between correctness and performance, with a more high-level approach than accuracy-focused alternatives. Some standard Mega Drive features remain unemulated: the TODO includes incomplete 68k exceptions, an unimplemented reset instruction and VDP rendering features. That makes ClownMDEmu a weaker fit for users whose priority is comprehensive hardware coverage.

Pricing

ClownMDEmu is free software under the AGPLv3 or any later version. Its sole plan, ClownMDEmu, costs nothing and includes the emulator as free software. There is no paid tier to weigh against the free version; the principal trade-off is the unfinished emulation work, not a feature cap or subscription term.

Platforms

ClownMDEmu supports web browsers, standalone desktop use and libretro-compatible hosts. The standalone frontend is written in C++20 using SDL3 and Dear ImGui. The core is designed for portability, but source compilation requires CMake and initialized Git submodules. The system scope is limited to the Genesis/Mega Drive.

Who it's for

Choose ClownMDEmu if you want a free Mega Drive core with browser, standalone and libretro access, or if its portable library design and debugging menus suit your development work. It is less suitable when you need complete emulation of standard Mega Drive features or want a single, straightforward desktop app without choosing a frontend.

Pros and cons

Pro: Three frontend routes give players and developers options for trying, running or integrating the core.

Pro: The relocatable, pointer-free state design supports save states and the possibility of multiple instances.

Pro: Free software under the AGPLv3 or later, with no paid plan.

Con: Several standard features remain unemulated, including work still pending in 68k exceptions, reset handling and VDP rendering.

Con: Building from source requires CMake and Git submodule setup, adding friction for users who want to get straight to playing.

Alternatives

RetroArch is the natural alternative if you want a free, open-source host available across Android, iOS, Linux, macOS, web and Windows; ClownMDEmu can itself be used through a compatible libretro host. Choose MAME instead if its Android, Linux, macOS and Windows availability better matches your setup; its plan notes that ROMs and copyrighted software are generally not included.

Manic EMU is another free option spanning Android, iOS, Linux, macOS, web and Windows. Lakka is worth considering for a free Linux, macOS, self-hosted or Windows option, but its hardware is not included and must be obtained separately.

BlastEm is a free, open-source alternative for Linux, macOS, web and Windows. emmd is a free option for iOS, Linux, macOS and Windows. EmulatorJS is a free, open-source option for Android, iOS, self-hosted and web use.

Genesis Plus GX is a free alternative for Linux and Windows; its source code is under a specific non-commercial license, and its standalone build is for GameCube and Wii. For broader category browsing, see Sega Genesis Emulators and Sega CD Emulators.

Verdict

ClownMDEmu is a sensible free choice for technically minded Mega Drive players and developers who value frontend flexibility, save states and a portable core. Its unfinished emulation features are the clearest reason to choose another emulator if broad hardware coverage matters more than its adaptable design.

Verdict

ClownMDEmu offers several ways to use its Mega Drive emulation core, including browser, standalone and libretro frontends. Its stated unfinished emulation areas matter to readers who need those features.

Where Specifiction places it

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